Influence of metal chloride modified biochar on products characteristics from biomass catalytic pyrolysis

Abstract

In this study, the pyrolysis temperature of peanut shells was optimized, and biochar was prepared and modified with HCl to obtain better surface characteristics and pore structure. The incipient wetness impregnation method was used to load one or two of NaCl, MnCl2, FeCl3 on HC, and their influences on the characteristics of the pyrolysis products were studied. The results show phenols have completed the evolution from methoxyphenols to benzenediols to alkylated phenols and aromatics from 440 °C to 660 °C. FeCl3 modified biochar has high phenol selectivity, reaching the maximum value of 46.63% when the loading is 8%. And it also has the highest aromatics selectivity. When the loading is 16%, the aromatic content is 38.33%. The selectivity of phenols and aromatics of MnCl2 is slightly lower than that of FeCl3, but it has the highest decarboxylation activity. The selectivity of NaCl is low, but it has the highest yield of aromatics at low loading. The advantage of bimetal modification is that it can take into account the selectivity of phenol and aromatics. The study indicates peanut shells have the potential to be widely used as raw materials and catalysts for the production of high value-added chemicals.